Folding blade cylinder for use in rotary folding machines

ABSTRACT

A folding-blade cylinder has a circumferential wall provided with one or more axially extending slots. A folding blade of springy sheet material is located within the cylinder and has an edge portion extending along the slot and another edge portion remote therefrom, with the other edge portion overlying a surface of the mounting element an edge of which faces towards the slot. Screws extend through openings in the other edge portion of the blade with such freedom that the blade can pivot about the edge of the mounting member and biasing springs normally tend to maintain the folding blade against such pivoting but permitting the same to yield and to pivot when a force is applied against it in requisite sense at its edge portion extending along the slot.

United States Patent [191 Hertrich [11] 3 ,820,774 June 28, 1974 FOLDING-BLADE CYLINDER FOR USE IN ROTARY FOLDING MACHINES ,[75] Inventor: Klaus I-Iertrich,Wa1dsiedluhg,

Germany FOREIGN PATENTS OR APPLICATIONS 429,288 5/1926 Germany 270/71 435,594 10/1926 Germany 270/71 1 Primary Examiner-Robert W. Michell Assistant Examiner-A. J. Heinz Attorney, Agent, or Firm-Michael S. Striker [57 ABSTRACT A folding-blade cylinder has a circumferential wall provided with one or more axially extending slots. A

folding blade of springy sheet material is located within the cylinder and has an edge portion extending along the slot and another edge portion remote therefrom, with the other edge portion overlying a surface of the mounting element an edge of which faces towards the slot. Screws extend through openings in the other edge portion of the blade with such freedom that the blade can pivot about the edge of the mounting member and biasing springs normally tend to maintain the folding blade against such pivoting but permitting the same to yield and to pivot when a force is applied against it in requisite sense at its edge portion extending along the slot.

9 Claims, 4 Drawing Figures PATENTED SH ma -mm" suenlurz PATENTEDJHHZB m4 31820.174

saw 2 0F 2 I FOLDING-BLADE CYLINDER FOR USE IN ROTARY FOLDING MACHINES BACKGROUND OF THE INVENTION .section of a book. It is known, therefore, toprovide such rotary folding machines which have folding-blade cylinders adjacent the circumference of which there are located one or more pairs of folding blades with the folding blades of each pair cooperating to effect folding of a sheet which is supplied to the cylinder. Depending upon the particular prior-art constructions, the known rotary folding machines must be capable of folding sheets whose thickness varies substantially. In other words, the folding machine may during one operational run he required to fold very thin sheets and during another operational run it may be required to fold very thick sheets. As a consequence it is necessary for the folding blades to be either so constructed that they are springy and can consequently yield to the extent necessary and dictated by the particular thickness of the material being folded, or else to make them adjustable so that the position of the two folding blades of a pair with reference to one another can be adjusted in dependence upon the thickness of the material to be folded.

In recognition of these problems, the prior art has already proposed to utilize folding-blade cylinderswherein one or both blades of a set that is the actual folding blade and the counter blade which cooperates with it are of a springy material. For details of such disclosures referencemay be had to German Pat. Nos. 435,594. and 623,291., for example. I Although initially thisappeared to be the answer t the problem which has been discussed above, it was found over a period of time that even thesearrangements were not entirely satisfactory. In particular, it was found that the higher speed of operations of the devices in question and the tendency to use material to be folded varying within wider and wider ranges, negated to a significant extent the advantages which were obtained by making one of the two cooperating blades of a springy material. Seeking for still further improvements, the art then proposed to make one of the blades of springy material and to mount the other blade so that it could be adjusted with reference to the springy blade in order to compensate for different thicknesses of the material to be folded. A further approach was to make both of the blades adjustable, as well as making them of springy material. The problem with these latter prilarge-dimensioned folding-blade cylinders, due to the space required for the installation.

.A further disadvantage of these latter types of priorart devices resides in the fact that, under certain circumstances and in certain of the devices, the pressure exerted by the two folding blades of a set of such blades upon the material being folded may be so great that the material will be damaged or destroyed. On the other hand it is possible in some of these devices that the pressure exerted by the two folding blades upon the material to be folded is too small and proper folding will not result, particularly if the material is rather thin. Again, the possibility exists that by change-over from operation with a thin to that with a thick or thicker material, damage might occur to the components of the cylinder. These disadvantages just outlined are mainly observed in the type of arrangement of the prior art where adjusting means are provided for moving one or both of the blades with reference to one another to compensate for the different thicknesses of the material being folded.

It is evident that the folding-blade cylinders known from the prior art are in need of further improvement. Such improvement has not, however, heretofore been forthcoming.

SUMMARY OF THE INVENTION Accordingly, it is a general object of the present invention to provide such improvements.

More particularly, it is an object of the present invention to provide an improved folding-blade cylinder for use in rotary folding machines, which is not possessed of the aforementioned disadvantages of the prior art.

A concomitant object of the invention is to provide such a folding-blade cylinder which can be produced much more economically than was heretofore possible.

An additional object of the invention is to provide such a folding-blade cylinder which has only relatively few components and even fewer components which are subjected to any wear.

Another object of the invention is to provide such a folding-blade cylinder in which the complicated arrangements required from the prior art for permitting adjusting of the blades of a set of blades with reference to one another can be omitted.

Still an additional object of the invention is to provide such a folding blade cylin'derin which the force exerted upon material being folded and located between the two blades of the cylinder will be relatively uniform irrespective of the thickness of the material, as long as this thickness remains within the operational range of the device, and will increase or decrease only slightly as a result of such thickness variations.

In pursuance of these objects and of others which will become apparent hereafter, one feature of, the invention resides in a novel article of manufacture, namely a folding-blade cylinder for use in rotary folding machines which, briefly stated, comprises a circumferential wall having at least one axially extending slot. A folding blade of springy sheet material is located within the confines of the wall and has two opposite edge portions one of which extends along the slot and the other of which is inwardly spaced therefrom. Mounting means mounts the folding blade in the cylinder and comprises an elongated mounting member extending along. the slot inwardly spaced therefrom and having a surface located at least substantially in a plane passing through the slot, and an edge facing towards the slot. Connecting members connect the blade to the mounting member with the other edge portion being juxtaposed with the surface so that in dependence upon pressure ezerted on the one edge portion, the blade can tilt about the edge of the mounting member out of the plane mentioned above and resilient means permanently urges the blade to a position in which it is located in the plane.

The folding blade of course cooperates with a counter blade, that is the second blade of a set of two blades. This second blade can be made fixed so that it cannot move and cannot flex with respect to the slot or to the folding blade itself, but according to a further concept of the invention the counter blade may also be so mounted that it itself is capable of tilting in the same manner as the folding blade. The counter blade need not be planar, but can also be of profiled cross section, that is of angular configuration.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary sectional view through a folding blade cylinder according to the present invention and illustrating one embodiment during the folding of 'a relatively thin material, the section being taken in direction transversely to the axis of the cylinder;

FIG. 2 is a view which is the same as that of FIG. 1 but which shows the embodiment of FIG. 1 while folding a material which is thicker than that being folded in FIG. 1;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail and firstly the embodiment illustrated in FIGS. 1 3, it will be seen that the folding blade cylinder D (see FIG. 3) has a circumferential wall which is provided with one or several (in the latter case they are circumferentially spaced) slots la. FIG. 3 shows two of these slots 1a, but the fragmentary larger-scale views if FIGS. 1 and 2 show only one such slot because this is all that is needed for an understanding of the invention.

Mounted within the cylinder C are two shafts 2, 3 which extend in axial parallelism with the longitudinal axis of the cylinder and of which one or both are turned about their respective longitudinal axis by suitable means known per se to those skilled in the art. The shaft 2 may have a flat provided on it, and a folding blade 6 may be secured to this flat, or as shown in FIGS. 1 and 2, an angular mounting member may be provided which at least in part overlies this flat and is connected to the shaft 2 by means of a plurality of screws or bolts 4 (one shown) spaced from one another longitudinally of the shaft 2. In the illustrated embodiment the folding blade 6 is mounted on the mounting member 5, although it could be mounted on the flat of the shaft 2 in which case the mounting member 5 could be omitted and the shaft 2 itself would be the mounting member.

The folding blade 6 is of a springy material, for instance spring steel or the like, and is elongated, having a strip-shaped configuration. One edge portion 6a of the blade 6 extends along the slot la as shown, whereas the other edge portion 6b overlies a surface of the mounting member 5 which is bounded in the direction towards the slot 1a by an edge 16. It will be appreciated that the mounting member 5 and the shaft 2 extend longitudinally of the slot 1a, as does the edge 16.

The blade 6 is provided in its edge portion 6b with a plurality of longitudinally spaced openings, it being understood that the blade 6 also extends along the slot la, and inserted through these openings and secured to the mounting member 5 for instance as by being threaded into tapped bores provided therein is a plurality of screws or bolts 7 (one shown) which act as positioning members for the blade 6. The shank of each bolt 7 is surrounded, at a side of the blade 6 which faces away from the mounting member 5, by two annular members or gaskets 8 and 9 and intermediate these members 8 and 9 the shank is further surrounded by a helical compression spring 10 which is retained in selectable axial compression between the members 8 and 9.

Mounted on the shaft 3 is a similar mounting member 30, being connected to the shaft 3 by means of longitudinally spaced screws or bolts 31. Connected to an arm of this angular mounting member 30 is a counter blade 1 1 by means of a plurality of longitudinally spaced bolts 32. The counter blade 11 is angled as illustrated and may be stationary, that is only the shaft 2 need be turnable while the shaft 3 can be stationary.

A counter cylinder 12 is provided, located adjacent the outer periphery of the circumferential wall 1 of the cylinder C and being shown only diagrammatically in F165. 1 and 2; the cylinder 12 is provided with one or more (one shown) folding elements 13. Details of the cylinder 12 are not illustrated because they are known per se and in any case do not constitute a part of the invention.

It should be kept in mind, however, that this cylinder 12 supplies sheets of material to be folded for instance thin sheets 14 as shown in FIG. 1 or thick sheets 15 as shown in FIG. 2, or again several superimposed sheets at one and the same time to the cylinder C. When the material 14 or 15 overlies the slot la in the wall 1, it is pushed inwardly by one of the elements 13 between the blades 6 and 11, thereby forming a fold as illustrated in FIGS. 1 and 2. The blade 6, being of springy material, can yield (in the drawing in upward direction as shown in FIG. 2) when necessary, that is when such yielding is dictated by the thickness of the material 15 as opposed to the thickness of the material 14 which does not necessitate such yielding. Because of the relatively significant distance by which the blade 6 can yield before sufficient resistance is encountered to cause it to pivot about the edge 16, from the position of FIG. 1 to the position of FIG. 2, it will be appreciated that fluctuations in the thickness of the material can be readily compensated for by yielding of the blade 6 all in itself, that is without pivoting about the edge 16 occurring. When, however, a certain thickness range is exceeded, that is when the material has for instance the thickness of the material 15, as shown in FIG. 2, than the springiness of the blade 6 alone is no longer sufficient to provide for such compensation and this would result in damage to the material because of excessively high pressure upon it, or an adjustment of the positions of the blades 6 and 11 with reference to one another would have to be carried out before such thicker material could be utilized.

Because of the present invention, however, the folding of material 15 whose thickness exceeds the range which can be compensated for by mere elastic yielding of the blade 6 results in initial elastic yielding of the blade 6 to the point where instead of continuing to so yield the blade 6 pivots or tilts about the edge 16 of the mounting member 5 to the position shown in FIG. 2, counter to the expansion pressure exerted by the biasing springs 10. This means that in the position shown in FIG. 2 the pressure exerted by the edge portion 6a upon the fold of the material 15, and the resistance exerted upon the folded material when the latter is to be subsequently withdrawn, is determined no longer by the characteristic line of the springy material of the blade 6 in accordance with the characteristics of the material and the cross-sectionof the blade 6, but is essentially determinedlby the characteristic lines of the springs 10.

It will be appreciated that a single adjustment in the pretension of the springs 10 makes it possible to so select the force with which the blade 6 will engage the folded material that up to a certain springy deflection of the blade 6 the force acting upon the folded material will increase relatively rapidly, for instance up to a force of kp (kilopond), whereas beyond this force at a deflection distance in the engaging region of 0.7 mm. it will continue to rise only slowly, for example to a maximum of 37 kp at a deflection distance (which is again measured in the region of contact) of 2 mm.

In the absence of the compression springs Wand of themounting via of the bolts 7 which permits the tilting of the blade 6 counter to the force of the springs 10, a springy displacement of the blade 6 through 2 mm. would cause the force acting upon the folded material to arise to approximately 87 kp, that is to a level which is not acceptable. Due to the present invention, how

amount which is necessary to reliably hold the thicker material, owing to the greater mass of such thicker material.

Coming, finally, to the embodiment illustrated in FIG. 4, it will be seen that this differs somewhat from the embodiment of FIGS. 1 3 in that the blade 11 is also mounted for tilting movement in the same manner as the blade 6.

In FIG. 4 like reference numerals designate like components as in FIGS. 1 3. In this embodiment, however, I have illustrated. the possibility of pivotally mounting the counter blade 11 in the same manner as the blade 6 is mounted for which purpose the mounting member 5a which is connected with the shaft 3 via the bolt 4a, has the blade 11 secured to it by means of a plurality of bolts 7a which, as in the embodiment of FIGS. 1 3, are spaced longitudinally of themember 5a, but which here are not tightened but instead of sufficient length to leave free space so that the member 1 1 can pivot. Of course, the size of the openings through which the-bolts 7a extend must be sufficiently large to permit this, as is of course also true with respect to the openings through which the bolts 7 extend in the blade 6. While springs may be interposed between the blade ever, the force will rise only by that approximate 11 and the arm of the member 5a on which the bolts 7a are secured, according to the currently preferred embodiment the blade 11 is in direct contact with this arm and springs 10a are arranged between that side of the blade 1 l facing away from the arm in question and the respective heads of the bolts 7a. In either case, the blade 11 can now also yield, under simultaneous axial compression of helical expansion springs 10a, and the rise in the increase of the force with which the folded material would be engaged by the blades 6 and 11 will thus be again influenced according to the considerations set forth above with respect to the blade 6.

It goes without saying that it is also possible of course to provide the blade 11 (either mounted as in FIGS. 1 and 2 or mounted as in FIG. 4) on the shaft 2, and to mount the blade 6 on the shaft 3. It will also be understood that it could be the shaft-3 which is turnable and the shaft 2 which is fixed, or that both shafts 2 and 3 could be turnable about their longitudinal axes by respective angular increments.

The operation of the present device is believed to be clear from the preceding description. However, reference may additionally be had to GDR Pat. No. 81,659 and corresponding US. Pat. application Ser. No. l 1 1,880, where a rotary folding machine is disclosed of the type with which the inventive device can be used in conjunction.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a folding-blade cylinder for use in rotary folding machines, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that from the standpoint of prior art, fairly constitute essential characteristics'of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. As a novel article of manufacture, a folding-blade cylinder for use in rotary folding machines wherein materials of various thicknesses are to be folded, comprising a circumferential wall defining a confined space and provided with at least one elongated slot; a mounting member mounted in said space so as to extend longitudinally of said slot and having a contact surface bounded by two edges extending longitudinally of said mounting member, said contact surface being at least partially located in a plane passing through said slot so that one of said edges is closer to said slot than the other edge; a resiliently yieldable elongated blade having a first end portion provided with'a plurality of apertures and juxtaposed with said contact surface so that one of the major surfaces of said blade extends in said plane when a portion of said major surface abuts said contact surface, and a second end portion extending beyond said mounting member and toward said slot; a

plurality of positioning members attached to said mounting member and extending through said apertures and preventing said blade from conducting a movement in said plane while permitting said blade to tilt about said one edge; biasing means mounted on said positioning means and acting on said first end portion of said blade so as to urge the same toward said contact surface of said mounting member; and a counter blade mounted in said space and having an edge portion extending along said slot and cooperating with said second end portion so as to permit gripping of the material to be folded between said edge portion of the counter blade and said second end portion with attendant yieldable displacement of said second end portion with attendant yieldable displacement of said second end por tion to an extent determined by the thickness of the material being folded, so that said surface portion is in contact with said contact surface when the material is relatively thin and said blade is permitted to tilt about said one edge when the thickness of the material exceeds a predetermined value whereby the spring constant of said biasing means is combined with the spring constant of said blade.

2. An article of manufacture as defined in claim 1, and further comprising an additional mounting member similar to said first-mentioned mounting member and mounted within said space; and wherein said counter blade is mounted on said additional mounting member.

3. An article of manufacture as defined in claim 2, wherein said counter blade has an additional edge portion spaced from said edge portion thereof and provided with a plurality of additional positioning members similar to said first-mentioned positioning members and extending through said additional apertures and attached to said additional mounting member so as to connect said counter blade to said additional mounting member.

4. An article of manufacture as defined in claim 3, and further comprising additional biasing means mounted on said additional positioning means and acting on said additional edge portion of said counter blade so as to urge the same toward said additional mounting member and permitting said counter blade to at least partially lift ofi said additional mounting member in response to insertion of relatively thick material between the first-mentioned edge portion of said counter blade and said second end portion of the firstmentioned blade.

5. An article of manufacture as defined in claim 4, said additional edge portion of said counter blade having an additional edge extending longitudinally of said additional mounting member; and wherein said counter blade is permitted to tilt about said additional edge against the action of said additional biasing means.

6. An article of manufacture as defined in claim 1, wherein said blade is of spring steel.

7. An article of manufacture as defined in claim 1, wherein said positioning members are threaded connectors.

8. An article of manufacture as defined in claim 1, wherein said biasing means comprises helical expansion springs.

9. An article of manufacture as defined in claim 1,

wherein said biasing means comprises biasing springs. 

1. As a novel article of manufacture, a folding-blade cylinder for use in rotary folding machines wherein materials of various thicknesses are to be folded, comprising a circumferential wall defining a confined space and provided with at least one elongated slot; a mounting member mounted in said space so as to extend longitudinally of said slot and having a contact surface bounded by two edges extending longitudinally of said mounting member, said contact surface being at least partially located in a plane passing through said slot so that one of said edges is closer to said slot than the other edge; a resiliently yieldable elongated blade having a first end portion provided with a plurality of apertures and juxtaposed with said contact surface so that one of the major surfaces of said blade extends in said plane when a portion of said major surface abuts said contact surface, and a second end portion extending beyond said mounting member and toward said slot; a plurality of positioning members attached to said mounting member and extending through said apertures and preventing said blade from conducting a movement in said plane while permitting said blade to tilt about said one edge; biasing means mounted on said positioning means and acting on said first end portion of said blade so as to urge the same toward said contact surface of said mounting member; and a counter blade mounted in said space and having an edge portion extending along said slot and cooperating with said second end portion so as to permit gripping of the material to be folded between said edge portion of the counter blade and said second end portion with attendant yieldable displacement of said second end portion with attendant yieldable displacement of said second end portion to an extent determined by the thickness of the material being folded, so that said surface portion is in contact with said contact surface when the material is relatively thin and said blade is permitted to tilt about said one edge when the thickness of the material exceeds a predetermined value whereby the spring constant of said biasing means is combined with the spring constant of said blade.
 2. An article of manufacture as defined in claim 1, and further comprising an additional mounting member similar to said first-mentioned mounting member and mounted within said space; and wherein said counter blade is mounted on said additional mounting member.
 3. An article of manufacture as defined in claim 2, wherein said counter blade has an additional edge portion spaced from said edge portion thereof and provided with a plurality of additional positioning members similar to said first-mentioned positioning members and extending through said additional apertures and attached to said additional mounting member so as to connect said counter blade to said additional mounting member.
 4. An article of manufacture as defined in claim 3, and further comprising additional biasing means mounted on said additional positioning means and acting on said additional edge portion of said counter blade so as to urge the same toward said additional mounting member and permitting said counter blade to at least partially lift off said additional mounting member in response to insertion of relatively thick material between the first-mentioned edge portion of said counter blade and said second end portion of the first-mentioned blade.
 5. An article of manufacture as defined in claim 4, said additional edge portion of said counter blade having an additional edge extending longitudinally of said additional mounting member; and wherein said counter blade is permitted to tilt about said additional edge against the action of said additional biasing means.
 6. An article of manufacture as defined in claim 1, wherein said blade is of spring steel.
 7. An article of manufacture as defined in claim 1, wherein said positioning members are threaded connectors.
 8. An article of manufacture as defined in claim 1, wherein said biasing means comprises helical expansion springs.
 9. An article of manufacture as defined in claim 1, wherein said biasing means comprises biasing springs. 